So I have a '68 Volvo 122s with a b18 and a generator that doesn't always like to charge. Most of the time it doesn't, but it has started charging at a couple points. It was actually charging pretty fine for awhile, but then just stopped.

So far I've only tested the voltage regulator, by shorting terminal df to ground for a second or two, and watching the voltage at d+ and ground. That didn't do anything. (I might be off on the terminal names, I can't remember for sure. I was following a troubleshooting guide on the swem site.)

So now the million dollar question: do I have the generator rebuilt, or do I forsake originality and fit an alternator? *apparently* the generator was recently professionally rebuilt, but I don't trust the previous owner as much as I did at the time of sale.

I do value originality, but I value reliability more. So that probably answers my question. Ha. I don't plan on having any huge electrical loads though, only non-stock item *might* be rally lights.

But, if I am to upgrade to an alternator setup, should I use a 140/160 alt, or will one of the GM delco ones bolt right in, with a 140/160 alternator bracket? or any other alternators that bolt right in? I know of a pretty good source of 140's/160's and parts, so I think that might be the best option, unless a newer unit will bolt right in.

So I have a '68 Volvo 122s with a b18 and a generator that doesn't always like to charge. Most of the time it doesn't, but it has started charging at a couple points. It was actually charging pretty fine for awhile, but then just stopped.

So far I've only tested the voltage regulator, by shorting terminal df to ground for a second or two, and watching the voltage at d+ and ground. That didn't do anything. (I might be off on the terminal names, I can't remember for sure. I was following a troubleshooting guide on the swem site.)

So now the million dollar question: do I have the generator rebuilt, or do I forsake originality and fit an alternator? *apparently* the generator was recently professionally rebuilt, but I don't trust the previous owner as much as I did at the time of sale.

I do value originality, but I value reliability more. So that probably answers my question. Ha. I don't plan on having any huge electrical loads though, only non-stock item *might* be rally lights.

But, if I am to upgrade to an alternator setup, should I use a 140/160 alt, or will one of the GM delco ones bolt right in, with a 140/160 alternator bracket? or any other alternators that bolt right in? I know of a pretty good source of 140's/160's and parts, so I think that might be the best option, unless a newer unit will bolt right in.

I got the Swedish Embassy kit. It's $100 for everything you need minus the alternator. You supply that. It has wiring diagrams and instructions that are easy enough to follow. I'm not sure which blocks were pre-drilled for alternators but my '67 was not.

Basically the swap is based on the GM swap to a one-wire AC Delco alternator. Ron Kwas at sw-em.com was even able to provide several part numbers for alternators of different outputs that will work well. The only extra step I had to take was to install a diode so my original AMP light would work as it should. I also took this opportunity to install an aftermarket voltmeter. At idle it charges 13.5 volts and rises to 14-14.5 with the throttle depressed. Now I can run a radio, lights, wipers, and fan and STILL be above 12 volts.

does anyone have pictures of an alternator mounted on a '67 or '68 or later pushrod red block? apparently they already have alternator brackets? trying to wrap my head around how all this stuff bolts up.

does anyone have pictures of an alternator mounted on a '67 or '68 or later pushrod red block? apparently they already have alternator brackets? trying to wrap my head around how all this stuff bolts up.

does anyone have pictures of an alternator mounted on a '67 or '68 or later pushrod red block? apparently they already have alternator brackets? trying to wrap my head around how all this stuff bolts up.

I've been meaning to take pictures of mine since I saw this, and I finally got around to doing it today. Excuse the ****ty cell phone pics:

Popped a GM Denso into mine this summer. I basically ripped off Ron's (SwEm) design since I'm cheap and have a welder, but its been great so far! I think its 70 amps and holds 13.9 at idle. Compared to my 35 amp gen that didn't do squat below 1200 rpms.

Popped a GM Denso into mine this summer. I basically ripped off Ron's (SwEm) design since I'm cheap and have a welder, but its been great so far! I think its 70 amps and holds 13.9 at idle. Compared to my 35 amp gen that didn't do squat below 1200 rpms.

that's kinda what I was thinking of doing... any pictures of the bracket/setup you made, by chance? I'm a bit confused as to how it's mounted differently than a stock alt, and how the bracketry is different than stock. I can weld and fabricate fine, I just don't have a welder yet, so I have to borrow a friends'. And I'm cheap too. Well, actually, more like just a broke college student with way too many cars. Ha.

I can get a 140/160 alt, voltage regulator, brackets and everything I need to fit it, for basically free, since I did some work for an old Volvo guy. But the reliability and condition of the alt would be a big question mark at 40 years old. So I don't know if I should just get one of those and maybe get it rebuilt, or go for the peace of mind of denso unit.

that's kinda what I was thinking of doing... any pictures of the bracket/setup you made, by chance? I'm a bit confused as to how it's mounted differently than a stock alt, and how the bracketry is different than stock. I can weld and fabricate fine, I just don't have a welder yet, so I have to borrow a friends'. And I'm cheap too. Well, actually, more like just a broke college student with way too many cars. Ha.

I can get a 140/160 alt, voltage regulator, brackets and everything I need to fit it, for basically free, since I did some work for an old Volvo guy. But the reliability and condition of the alt would be a big question mark at 40 years old. So I don't know if I should just get one of those and maybe get it rebuilt, or go for the peace of mind of denso unit.

I'd just get the Denso and be done. They usually have a lifetime warranty too.

There's an SI alternator on my Grand Prix, maybe if I'm feeling saucy I'll pull it off and give it a test fit.

And here it is:

Compared to the stock one:

It sits about where the Denso does in relation to the crank and w/p pulleys. I didn't think to take a pic of the sides of them, sorry about that.

The pivot bolt on the B18 is a 1/2" shank, the one for the SI is about 3/8".

And, as measured by the finest Harbor Freight caliper and screwdriver (because my tools are scattered between a few different cities right now, and I couldn't find a more suitable straightedge), the distance from the front of the original alternator's pulley to the mounting face of its pivot point is 3".

hmm. interesting. I wonder how hard it would be to fab up a different bracket for it?

Well, this factory bolt location is part of the block casting, so it's not like you could just unbolt it. It looks like, because of the size of that part of the casting, the aftermarket brackets won't bolt onto the block, either (I'm assuming the hex section is supposed to replicate the later mounting location, and that the earlier blocks don't have that extra material over the forward boss). If that's the case, then what's the deal with that engine with the SI on it? I wonder what they did for accessory pulleys, because my original pulleys sure as hell don't line up.

all this theorizing without visualizing it on my car is making my head hurt. my car's in storage about an hour away from me for the winter, so I think I'll throw some new brushes in my generator next spring to see if I can get that to work, and get it home. and then just grab a cheap SI alternator at the junkyard to play with and try to figure out a solution for.

All the time you're spending figuring out what to do about mounting the thing - fuggeddaboudit. Buy the SW-EM kit. Yeah, it's a hundred bucks. It's also rugged as hell, works great, it's easy to install, and Ron's instructions are excellent. Use the time and imagination you were going to devote to this on something for which there isn't such a no-brainer solution.

BTW, the 10/12SI alternators are *not* one-wire, they're three-wire. Marginally more complex to set up, but they work better. And you get to keep your red amp light in the dash. Most people find that it's worthwhile. And like I say, Ron's instructions are excellent, so you should have no problems.

One thing I'll suggest as an addendum/modification of Ron's approach. Ron's kit is set up to connect the voltage sensing wire (the third wire of the three, the one that doesn't connect to the amp light or the battery) to the battery output stud on the alternator. While this will work, it means the alternator is measuring the voltage at the "best case" point. It's better to connect the wire to the power distribution stud (which should be mounted on the firewall). That way it'll give you a more accurate reading of actual voltage in the system.

All the time you're spending figuring out what to do about mounting the thing - fuggeddaboudit. Buy the SW-EM kit. Yeah, it's a hundred bucks. It's also rugged as hell, works great, it's easy to install, and Ron's instructions are excellent. Use the time and imagination you were going to devote to this on something for which there isn't such a no-brainer solution.

BTW, the 10/12SI alternators are *not* one-wire, they're three-wire. Marginally more complex to set up, but they work better. And you get to keep your red amp light in the dash. Most people find that it's worthwhile. And like I say, Ron's instructions are excellent, so you should have no problems.

One thing I'll suggest as an addendum/modification of Ron's approach. Ron's kit is set up to connect the voltage sensing wire (the third wire of the three, the one that doesn't connect to the amp light or the battery) to the battery output stud on the alternator. While this will work, it means the alternator is measuring the voltage at the "best case" point. It's better to connect the wire to the power distribution stud (which should be mounted on the firewall). That way it'll give you a more accurate reading of actual voltage in the system.

I second this. Sometimes I'd rather spend that extra dollar to not even have to worry about it and that's exactly what you can do with the SW-EM kit. While you're at it, put in a voltmeter so you know exactly what you're charging system is doing. You won't regret buying the kit. The only problem I ran into was when using a one wire Delco alternator my AMP light would stay on when the car was off and turn off when the car was on. Add in a diode if necessary.

Don't add a diode. There are good reasons to use a three-wire alternator, and it's not at all difficult to wire it properly. Just follow Ron's instructions with the SW-EM kit. Just get a 10/12si alternator and wire it up right. It's easy. Really. I promise.